After reading and answering this question, it caused me to believe that in Greek mythology, there were a lot of nymphs. They were nature spirits, and so, there are a lot of types of nymphs.
Cloud - Nephelai (Cloud-Nymphs)
Grass - Leimonides (Pasture Nymphs)(Close enough to grass)
Flower - Anthousai (Flower Nymphs)
All from here.
So what other nymphs were there?